The present invention relates generally to textile wet treatment machines and more particularly to a carrier for supporting packages of textile material during processing in a wet treatment machine such as, for example, textile yarn package dyeing machines and to a novel package retaining cap for use with such carrier.
Textile package dyeing machines normally have a cylindrical pressurizable vessel into which packages of textile material to be wet processed, e.g., yarn packages wound on cylindrical spools, are arranged in vertical stacks on supporting vertical tubes arranged in spaced relation over the interior of the dye vessel. Such dyeing machines basically are of two types, commonly referred to as vertical dyeing machines, i.e., wherein the cylindrical vessel is oriented vertically with an openable lid at the upper end of the vessel for vertical insertion and removal of yarn packages to be dyed, and horizontal dyeing machines, wherein the cylindrical vessel is oriented horizontally with an openable lid at one end for horizontal insertion and removal of yarn packages to be dyed.
In both horizontal and vertical dyeing machines, it is conventional practice to support the yarn packages on a removable carrier which, in the case of vertical machines, can be lifted and lowered and, in the case of horizontal machines, can be horizontally transported on tracks or conveyors, for inserting and removing the yarn packages into and from the dye vessel. Conventional carriers of this type basically comprise a base with a plurality of upstanding tubes mounted in a spaced arrangement to the base. Yarn packages are slidably mounted over the upper ends of the tubes in a stacked arrangement and are secured by a cap threaded onto a compatibly threaded upper end portion of each tube. The upstanding tubes are hollow and perforated and communicate with concentric openings formed through the base to permit dye liquor to flow axially through the tubes and radially through the yarn packages.
While such carriers function satisfactorily and advantageously when supporting a full capacity of yarn packages, difficulties are encountered in dyeing smaller lots of yarn packages which do not require each tube to be fully stacked with yarn packages. In such cases, it is highly undesirable to fill the dye vessel with dye liquor to the same volume utilized when dyeing a full capacity of yarn packages. Accordingly, the volume of the dye bath is reduced commensurate with the number of yarn packages actually being dyed, but, since the lesser volume of the dye bath will result in the level of the bath being below the upper end of the perforated package-supporting tubes, appropriate measures must be taken to cover the exposed perforations. Conventionally, this is accomplished in one of two manners, either by placing a tubular cover over the exposed length of each perforated tube to block the perforations in the tube or by situating one or more volumetric displacement elements within the carrier or otherwise within the dye vessel to raise the level of the lesser volume of dye liquor to the level occupied during full capacity dyeing. Disadvantageously, however, volumetric displacers increase the risks of potential contamination of the dye liquor, while the tubular covers may not fully seal the exposed perforations in the package-supporting tubes, thereby risking the possibility that may be drawn into the pump of the dyeing machine used for circulating the dye liquor.
An alternative form of textile package carrier is disclosed in pending U.S. patent application Ser. No. 08/134,912, filed Apr. 12, 1993, and now U.S. Pat. No. 5,442,939 entitled CARRIER FOR SUPPORTING TEXTILE MATERIAL IN A WET TREATMENT MACHINE. The carrier of such invention utilizes a plurality of posts extending upwardly from a carrier base with each post having a longitudinal package supporting portion adjacent the base of sufficient length to support a minimum number of textile packages and a longitudinal spindle portion extending outwardly from and in alignment with the package supporting portion. Any selected one of several available package supporting adapters of varying lengths may be placed about the spindle portion of each post, or alternatively adapters may be omitted from each spindle portion, to give the carrier the ability to selectively support differing numbers of packages about the posts as determined by the absence of, or the presence and length of, package adapters on the posts. A conventional form of package retaining cap is threadedly mounted on the spindle portion of each post and advanced along the length thereof sufficiently to rest in retaining engagement with the uppermost package mounted on the post. In this manner, the carrier is enabled to be used for wet processing operations with less than a full capacity of textile packages, but without the necessity of utilizing blocking covers or volumetric displacer elements as in the prior art.